It is well known that in the construction of a pneumatic tire, a plurality of tire plies are layed up on a tire building drum. Such plies are formed from calendered fabric sheets in which cords of steel, polyester, or other appropriate materials are embedded in a rubber or elastomeric sheet. Those skilled in the art readily understand that such calendered fabric sheets provide the plies which are employed as the primary fortification or reinforcement of pneumatic tires during both manufacture and in use.
It has been found that tire integrity, uniformity, durability, and performance are a function of the uniformity of the distribution of the cords within the calendered fabric sheets from which the plies are formed. Accordingly, it is important to monitor such cord distribution in the calendered sheets to maintain the same within acceptable tolerances. In the prior art, such monitoring and measuring of the cord distribution has been totally manual. The previously known measurement methods have been slow, not always accurate, and time consuming. The prior processes and techniques have not been given to ease of locating the centers of the cords and, accordingly, measurements of cord distribution have been generally taken with respect to the outer surfaces of the cord, which measurement techniques have been found to be highly subjective in nature and, accordingly, not always accurate. There is a need in the art for an apparatus and technique for determining cord distribution in a fabric ply sheet which is accurate, reliable, and quickly and automatically achieved.